Scientists believe the interactions began after an orca called "White Gladis" experienced a “critical moment of agony" involving a boat
After a number of instances in which orcas appeared to purposefully sink sailboats in Europe, some researchers are theorizing that the killer whales may have taught each other to do so in the aftermath of a prior traumatic incident. But the reason why remains up for debate.
Reports of aggressive encounters between orcas and sailboats in the Iberian coast off of Europe began in 2020, according to Maritime Executive, and the incidents have ramped up since then.
Killer whales have since sunk three boats there, targeting the rudders of sailboats less than 15 meters in length, according to Live Science, which reported that "experts now believe the behavior is being copied by the rest of the population."
Alfredo López Fernandez, a marine biologist the University of Aveiro in Portugal, told Live Science he believes the interactions began after one orca, called "White Gladis" by scientists, experienced a “critical moment of agony" involving a boat.
"That traumatized orca is the one that started this behavior of physical contact with the boat," the biologist told the publication.
Other orcas then began imitating White Gladis' actions and participating in the attacks on boats' rudders. "The orcas are doing this on purpose," said López Fernandez.
In a May 4 incident in the Strait of Gibraltar, a group of three orcas pierced the rudder of a sailboat. "The little ones shook the rudder at the back while the big one repeatedly backed up and rammed the ship with full force from the side," the boat's skipper, Werner Schaufelberger, described to German magazine Yacht, per Live Science. "The two little orcas observed the bigger one's technique and, with a slight run-up, they too slammed into the boat."
Everyone on board was rescued, but that boat ended up sinking when it returned to port.
According to Maritime Executive, scientists from research center CIRCE found that three whales from the same pod are involved in the boat rudder interactions — but some experts think the behavior is more playful than aggressive.
"They appear to be engaging with sailboats as a form of entertainment," the publication noted. Meanwhile, marine biologist Dr. Renaud de Stephanis told the BBC, “From what I’m seeing, it’s mainly two of those guys [the Gladises] in particular that are just going crazy. They just play, play and play. . . . It just seems to be something they really like and that’s it.”
“I’ve seen them hunting,” the biologist added. “When they hunt, you don’t hear or see them. They are stealthy, they sneak up on their prey. I’ve seen them attacking sperm whales - that’s aggressive....but these guys, they are playing."
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There has never been a fatal orca attack on a human in the wild, per Maritime Executive. And though the boat attacks are alarming for both sailors and whales — Iberian orcas are considered critically endangered by the IUCN Red list — the risk of an encounter remains low. "In more than 500 interaction events recorded since 2020 there are three sunken ships. We estimate that killer whales only touch one ship out of every hundred that sail through a location,” Lopez Fernandez told Live Science.
It’s possible that the Iberian orcas’ recent preoccupation with ambushing boats is nothing more than a “fad” — a behavior they adopt for a short period of time and then abruptly stop, per Live Science.
"They are incredibly curious and playful animals," Deborah Giles, an orca researcher at the University of Washington, told Live Science.
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